Apparatus for producing carbon



C. MATLOCK' APPARATUS FOR PRODUCING CARBON Original Filed Jan. 5, 1921 ATTORNEY Patented Aug. 28, 1928.

' UNITED STATES PATENT OFFICE.

CHAUNCEY MATLOCK, OF BROOKLYN, NEW YORK, ASSIGNOR TO MONROE-LOUISIANA CARBON COMPANY, OF MON ROE, LOUISIANA, A CORPORATION OF DELAWARE.

APPARATUS FOR PRODUQING CARBON.

Original application filed January 5, 1921, Serial No. 435,071. Divided and this application filed June 11, 1923. Serial No. 644,722.

This invention relates to the disassociation of the constituents of hydrocarbons and particularly to the disassociation of a hydrocarbon gas and the collection and recovery of the elemental carbon therefrom.

The object of my invention generally is to obtain an improved quality of carbon black from a hydrocarbon gas, for example natural gas, and to recover a larger proportion of the carbon constituent per unit volume of gas than has hitherto been possible with many known methods and devices.

A further object of my invention is a method and an apparatus for producing carbon black whereby the cost of installation and operation of the plant are reduced to a minimum and the efficiency of production generally improved, the operation accordingto this method being continuous and nonintermittent.

This application is a division of my copending application, Serial Number 135,071,

; filed January 5, 1921, Patent Number 1,458;

351 which has been reissued into Reissue Number 16,765.

The method and apparatus generally used for producing carbon black on a commerclal scale consists in partially burning the natural gas or other hydrocarbon gas by means of a multiplicity of miniature burners and cans ing the individual flames or products of combustiouto playupon chilled surfaces whereon a portion of the carbon content is deposited and subsequently scraped off. The black thus obtained often contains metallic iron and scale and often contains other impurities and characteristics which render it unsuitable for certain of its uses. Moreover, the apparatus usually employed is crude and comparatively expensive to build and the collecting devices wear very rapidly, necessitating periodic replacements. Further, the usual commercial plants are cumbersome and occupy large areas.

Certain other methods have been suggested for the manufacture of carbon black, but none tively large furnace by supplying to the fur- 4 nace and to the gaseous flame predetermined quantities of air which are insufiicient for complete combustion, and the passing of the resultant products of combustion through a suitable collector for isolating the liberated carbon therefrom.

I have found that the quality of the carbon and carbon yield are substantially improved by a careful and accurate adjustment of the mixture of air (oxygen containing agent) and gas supplied to the furnace, and particularly by the manner in which the mixture is accomplished. For example, the admission of the air into the furnace beneath the burners gives good results, particularly when the air is automatically supplied in regulated quantities and at predetermined pressures (preferably only slightly above atmospheric). I obtain excellent results by automatically mixing the gas and air according to predetermined proportions before the mixtiire reaches the flame zone and l prefer also to employ these methods and devices in connection with certain other of my improvements in the manufacture of carbon as will appear hereinafter.-

In the practice of my invention 1 have devised a furnace with a battery of comparatively large burners or gas intakes with their mouths opening into the furnace at points a short'distance from-the bottom of the chamber. The hydrocarbon gas issuing from the gas intakes is caused to burn very slowly and lazily by supplying thereto predetermined quantities of air, but insufficient to reduce complete combustion, the gas being supplied at a pressure above atmosphere and the burning taking place at the desired pressure. Means are provided for regulating the pressure and the volume of the gas supplied to the burners and for automatically regulating and supplying the exact quantity of air required to the furnace. Preferably, this means consists of a rotary fan or blower, as good results have been obtained therewith. The resulting products of combustion and unburned gases are more or less confined or trapped in the furnace and the temperature thereof elevated to the desired degree for most efficient operation. Provision is made for the gradual exhaust of the .resulting products and gases through a restricted outlet near the top of the furnace. The hot products with the liberated carbon are conducted from this outlet through a cooling system or circuit of restricted dimensions for reducing the temperature, increasing the density and reducing the volume and thence to a collector where the carbon is separated from the other constituents. The collector is preferably either of the electrical precipitation type or of the closed bag filtration type. A fan or blower together with an exhaust regulator is provided for the purpose of assisting to maintain the natural draft of the products of combustion and to impart thereto the required velocity through the restricted passages of the cooling system, as I find that the efliciency of operation and pro duction is thereby increased. This fan maybe dis ensed with, however, in cases where the desired draft is otherwise obtained. The hot gases with the liberated carbon in suspension are drawn through the conduits atsuflicient velocity to carr along therewith the greater portion of any occulent carbon which may be precipitated in the cooling pipes, and substantially the whole of the liberated carbon which leaves the furnace with the gases is borne to the collector. and thence recovered.

the apparatus. There are provided a number of burners 2 (only two being illustrated) .which are supplied with a hydrocarbon gas,

for example natural gas, through a supply pipe 3 leading to a gas main 4. A valve 5 is indicated for controlling the gas circuit and preferably the circuit is provided with a. gas pressure regulator (not illustrated) for the purpose of supplying gas at a substantially uniform and constant pressure. There is a rotary fan or blower 7 interposed in the supply pipe 3 which serves as a rotary mixing 5 and air introduced through machine for the gas introduced through valve ipe 6 at the cen-- ter of the mixer, this fan oh mixer serving also as a means for varying the pressure of the intermixed gases which are carried on through the supply pipe 3 to the burners in predetermined proportions so that burning is effect ed in any desired way. The quantity of gas and air lntroduced into the mixer 7 is deter-- mined by the setting of the gas valve 5 and the air valve 8. It is noted that the burners are positioned near the base of the furnace so that the whole interior thereof is usable for the intermixing and combustion of the consumed and partially consumed gases and vapprs but it is understood, however, that this arrangement may be varied in some respects Without departing from the spirit of the invention.

Near the top'of the furnace 1 there is provided a restricted outlet 9 which leads to a cooling'circuit or system 10. From the cooling system 10 the furnace outlet leads through a heater 11 and from thence to a collector 12.

The cooling system consists of a pipe of re-" stricted dimensions as comparedto the volume of the furnace and a water spray system 13 which may continuously spray cold water upon the cooling pipes 10 for the purpose of reducing the temperature of the products of v combustion passing therethrough. The degree of cooling may be regulated by adjusting the supply of water. to the spraying system as for instance b 'means of a valve 14 in the water main. Ti observed to slightly diminish in cross section 1e cooling pipes 10 are from the front to the rearmost end. This reduction in cross section may be made because the products of combustion may be reduced in volume asthey are cooled by contact with the coolingpipes. The resulting increase in density of the gases passing through the cooling and collector system promotes the eflicient separation of the carbon from the other gases.

Two different types of collectors are illustrated, collector 12 bein of the bag filtration type and collector 12 fFig. 2) being of the electrical precipitation type. The collector 12 consists generally of a container, preferably of cylindrical shape, with a hopper 15 on the lower part for collecting the carbon as it falls by ravity or is caused to fall from the filtration bags. The filtration bags are indicated diagrammatically at 16 whose open ends register with the openings 17 in the artition plate 18 carried b the container. he bags (only two of which are shown) may be Inn carried in any suitable manner and means blower being connected with the upper part of the collector container through a conduit 23. There is disposed within this conduit a regulating valve 24 whereby the exhaust or draft pressure may be regulated or adjusted to a nicety.

The operation of the system may be described substantially as follows:

The natural gas having been turned on (at a pressure above that of the atmosphere), the burners are lighted and the air regula tor 8 and blower 7 adjusted to supply positively the exact quantity of air and gas desired for the most efficient operation of the system and-the products of combustion resulting from the incomplete combustion of the natural gas gradually accummulate in the furnace until the upper part thereof is completely filled with the gases and the liberated carbon in suspension. The main gate 25 in the circuit being open, the products of com bustion with the sus ended liberated carbon begin to circulate through the cooling system 10 and the blower 22 together with its regulating valve 24 are adjusted to give an ex collector so that the great portion of the liberated carbon which leaves the furnace through the outlet 9 actually reaches the collector and is there filtered out and deposited into the hopper 15, the cleansed gases pass out through a conduit 23 and the blower 22. i

I have found that the bag collectors opcrate very efliciently to filter out the liberated carbon and that they work particularly well at temperatures below 225 F. Eflicient results for example have been obtained with the operation of the collector gases at a temperature of 170 F. to 225 1 I have also found that with the proper adjustment of the gas and air supplied to the furnace and with a proper balance of the system including the careful adjustment of the exhaust pressure and the degree of cooling that the carbon black recovered in the hopper 15 is a particularly desirable commercial product and is free from the above noted injurious constituents and undesirable qualities; moreover, the yield of carbon per unit of gas is found to be greater than the yield of carbon produced by many known methods and devices.

These results are noticeable to a certain degree under various conditions of operation, but are particularly marked with temperatures in the furnace running above 1200 F. For example, with temperatures in the furnace of 1400 F. to 1800 F. (as measured by pyrometer 28), and with careful adjustment of the air admitted into the furnace, both the yield and quality of carbon produced are with adjustments giving other percentages of these gases. It is also observed that with an adjustment such that the products of combustion and intermixed gases are all retained above the level of the burners 2, the yield and quality are good. For example, as indicated in Figure 1, there seems under certain conditions to be a clear and defined dividing line or blanket 29 between the gases 30 above and the air below this line, and the air entering the furnace and collecting beneath this blanket is probably preheated to a certain degree before it enters the combustion and dissocia-, tion space. per unit of gas at the higher temperature operation is probably due to the co-operation of all the elements of my process and apparatus, although it may be due in part to some dissociation of the carbon and hydrogen oi unburned gas which may reach the high tem- The increased yield of carbon perature regions of the-furnace without being burned by the flame. For instance, a portion only of the dissociated and liberated carbon recovered in the collector may come from the incomplete combustion while the remainder may be due to carbon which is thermally dissociated from unburned gas (CH methane and C 11 ethane) escaping through the flames into the high temperature regions of the furnace, the liberated hydrogen being burned to water. it is understood, however, that I do not limit my improvements to any particular theory of operation, as it may develop later that the good results obtained are based upon a different theory of operation and reactions taking place.

l have also found that the electrical precipitator cooperates to a particular degree with my other apparatus to produce a large yield of carbon per unit of gas, although I now prefer for certain reasons the bag filtration system.

F or the purpose of relieving the furnace l of the products of combustion or for other reasons an outlet 26 is provided and is disposed near the top of the furnace, a door 27 being positioned upon the upper end of the pipe 26 for the purpose of opening or closing the same. The heater 11 is in the nature of a steam chamber for preheating the cooled they pass through the collectors. By a proper adjustment of the cooling and exhaust system the gases may be expected to lose a portion of the water or vapor content and the elevation of the temperature above the dew point before passage through the collector insures the passage of the greater portion of the water content through the collector and out with the cleansed gases as a water vapor.

In each of the various forms of the invention a substantially uniform mixing of the hydrocarbon and fuel is obtained prior to, or in the early stages, combustion and the partial combustion reaction is carried on under uniform conditions which may be adjusted to suit the characteristics peculiar to any type of hydrocarbons which may be used in the production of the carbons. The disturbing influence of cooling plates,ung1.1arded inflow of air and other influences which might effect the combustion reaction and impair the quality or yield of the carbon are therefore excluded.

In accordance with the requirements of the patent statutes I have set forth only one form of the many forms my invention is capable of assuming. The drawings being purposely diagrammatic for convenience in illustration, and it is understood that the claims annexed hereto are not to be construed as limited to the exact methods and devices illustrated, except as is specifically recited therein, but are to be construed to cover all modifications coming Within the spirit of the invention.

Having thus described my invention, what I desire to secure by Letters Patent of the United States and claim is z 1. In an apparatus for separating and recovering carbon blackfrom a hydrocarbon gas, the combination of a furnace; gas burners positioned within said furnace; a gas mixing machine adapted to receive gas and air in proportional quantities insufiicientfor complete combustion, and to agitate and positively mix the same; and connections between several gas burners and the mixing machine.

2. In an apparatus for separating and rememes covering carbon black from a hydrocarbon gas, the combination of a furnace and burn ers within the furnace adapted to receive and partially burn the hydrocarbon gas and means for agitating and positively mixing gas and air and supplying the mixed gas and air to said burners.

3. In an apparatus for separating and recovering carbon black from a hydrocarbon gas, the combination of a number of burners, a device for supplying a mixture of gas and air to such burners, means for regulating the supply of gas and air to said device, means for agitating and mixing the regulated supplies of air and gas, a cooling system for receiving the resulting products of combustion and reducing the temperature thereof, and a collector adapted to receive the cooled products and isolate the liberated carbon.

4. In an apparatus for separating carbon from a hydrocarbon gas, the combination of a furnace of comparatively large dimensions, burners disposed in the lower part of such furnace, means for supplying air and gas to said furnace and for regulating the supply of air and gas, a device for mechanically mixing said regulated supply of air and of gas, and means for conveying said mixed gases to and distributing them to the burners in said furnace, a cooler for receiving the hot products of combustion from the furnace, a collector for isolating the-liberated carbon from the cooled product and means for exhausting the products of combustion from the upper part of the furnace through the cooler and collector.

5. In an apparatus for separating and recovering carbon black from a hydrocarbon gas, the combination of a furnace; burners positioned within said furnace; a mixing device for mechanically stirring and mixing said gas and air; control means for admitting gas and air into said mixing device; and a conduit intermediate the burners and the mixing device.

In testimony whereof, I aifix my signature.

CHAUNGEY MATLOCK. 

